The invention relates to a method which is used to emit messages from a multiplicity of data sources in a data network to a vehicle. The invention also includes a server device which can be coupled to a data network.
In the case of vehicles (road vehicles, for example automobiles and/or trucks), it is possible to set up a communication connection to a data network, for example the Internet, via a mobile radio interface using a mobile radio module even while traveling. As soon as such a data connection has been established, different devices of the vehicle or different computer programs executed by a computer device in the vehicle can then set up network connections to servers in the data network. If a connection to an Internet provider (ISP—Internet Service Provider) is established using a UMTS mobile radio connection (UMTS—Universal Mobile Telecommunication System) for example, the Internet provider can assign an Internet address to the mobile radio module or a gateway or router of the vehicle connected downstream of said mobile radio module. The individual devices or programs can then interchange data with Internet servers independently of one another on the basis of this Internet address (IP address) and other protocols (TCP—Transfer Control Protocol, UDP—User Datagram Protocol and the like).
A data service which is particularly important in connection with vehicles and can be provided in a data network is the transmission of current traffic data or data relating to a state of a road. For this purpose, it is known practice to determine such data with the aid of vehicles in the traffic which transmit their current travel speed and friction values of a road surface, which are determined using an ESP (ESP—Electronic Stabilization Program) for example, to corresponding servers in the data network. The collected data are then distributed by the server to the vehicles again, with the result that the information relating to the current traffic situation and the instantaneous state of the roads becomes available in each vehicle.
The transmission of data between a (stationary) network service provider, on the one hand, and a vehicle, on the other hand, which is enabled using a mobile radio interface, is naturally band-limited, that is to say only a limited number of data items can be transmitted in a predetermined interval of time. However, since it is possible for individual devices and programs to maintain data connections to network servers independently of one another, it is not possible to predict whether a bottleneck cannot result during data transmission. If this situation occurs once, this may even endanger the safety of the vehicle occupants. If, for example, the bandwidth of the mobile radio interface is used completely to transmit film data relating to a feature film which is played back in the vehicle, this may result in delays in the transmission of more important data, for example traffic data or warnings of black ice.
DE 10 2008 061 304 A1 discloses a communication device for a vehicle for wirelessly transmitting data which are relevant to the vehicle, which device comprises two communication units. A first unit is used to transmit first data and the second unit is used to transmit selected second data to the vehicle. The decision regarding which of the units data are transmitted to is made in this case on the basis of a priority of the data. In addition, the communication units may be designed in such a manner that, upon receiving data, they decide whether a received message is a message specifically intended for the vehicle or a general message for a multiplicity of vehicles. However, the disadvantage of this last aspect is that the data must first of all be transmitted via the radio interface before a decision can be made on their relevance.